This invention relates to a control handle for controlling the speed and direction of travel of pallet trucks and other related vehicles.
Specifically, this invention relates to a control handle that may be used by an operator both while riding on a pallet truck and while walking along the side the truck. Such control handles have typically included a pair of twist grips which are rotated to control the speed and direction (forward and reverse) of travel of the truck. The twist grips are intended to be rotated in the same direction as the drive wheel of the truck; thus, rotating the twist grips forward will cause the vehicle to move in the forward direction, and rotating the twist grips down or in the reverse direction will cause the truck to move in the reverse direction. Operating the twist grips in the direction opposite to the direction of rotation of the drive wheel can also accomplish a slowing or braking function, although a separate brake is available to the operator. Moving the control handle from side to side controls steering of the truck.
It is sometimes desirable to operate a truck while walking along side of it, as shown in U.S. Pat. No. 5,245,144. In this mode of operation, one of the operator's hands grips the control handle to provide positive steering control of the truck, and some mechanism is provided to control speed and direction of travel. In the U.S. Pat. No. 5,245,144, a steering control unit includes a pair of switches on either side of the control handle which are actuated to move the truck at a predetermined slow speed; vertical movement of the steering control arm controls braking of the truck.
In other trucks, the steering control arm is oriented toward the operator's platform. In this type of vehicle, the control handle will be located over the truck's power unit, not ahead of the truck and waist high. In such vehicles, control of the truck has been by use of existing twist grips, butterfly buttons on the steering arm, separate push/pull buttons and the like.
It would be desirable to provide an integrated control handle for a pallet truck which permits walk-along control while making use of the existing twist grips and without the need for separate, complex control switches or circuits.